Method of making loosening stretchers for cables, rods and the like



Sept. 13, 1932. v p, sTRElT 1 871370 METHOD of MAKiNG LOOSENING STRETCHERS FOR CABLES, RODS, AND THE LIKE Filed March 15, 1929 Fig. 3

Patented Sept. 13, 1932 UNITED STATES PATENT OFFICE ALBERT PAUL STBEIT, OF FRANCE I METHOD OF MAKING IlOOSElll'ING S'I'BE'ICHEBS FOB CABLES, RODS AN D THE LIKE Application filed larch 15, 1929, Serial Io. 847,263, and in France Mamh 20, 1928.

The present invention relates to a method of manufacturin stretchers for cables, rods and the like. he known stretchers, and

' chiefly those employed for-the guy wires of 6 aeroplanes, usually comprise a main central body having at the ends suitable tapped parts with right and left hand threads, optionally equal, into which are inserted corresponding threaded rods connected to the cable or wire 10 to be stretched.

In this disposition, due to the small diameter of the said threaded rods, it is not feasible to provide recesses in the rear of the parts forming the nuts and thus the said nuts must be threaded upon their whole length.

In this manner the functioning is defective and the stretching operation lacks precision. The improved stretcher according to the invention will obviate all such defects. Itcomprises tapped parts having in the rear suitable enlarged chambers, thus avoiding all drawbacks and enabling the manufacture of a a stretcher of reduced weight and great strength. On the other hand, the length of the thread in engagement is constant, and it is thus feasible to accurately measure the effort of tension exercised on the cable or the like to be stretched, irrespective of theposi- 4 tion of the stretcher.

According to my present invention, I form or take a hollow metal blank whose bore corresponds to the size of the chamber it is desired to obtain, and then narrow or reduce the end which is to be tapped, by transverse pressure, and during this operation, the portion subjected to such pressure is held in such a manner as to prevent any substantial longitudinal flow of the metal. For instance, P

the blank may have transverse annular external ribs fitting into corresponding grooves on the pressure-exerting tool or device. The operation will therefore result in compressing a portion of a blank not only to a reduced diameter, but to a greater density, the fibres of the metal being very compact in the portion.which has thus been subjected to pressure, and the metal in this portion (which is subsequently tapped) therefore has no structural defects, and the tapped thread will have exceptional strength.-

showing respectively a stretcher piece during 5 the pressing operation, and thepiece after the said operation. a

Fig. 3 is an axial section of a finished stretcher nut.

Fig. 4 is an external view of a stretcher consisting of two parts analogous to Fig. 3.

Figs. 5 and 6 are res ectivel an elevatilonal and an end view ofpa stretc er holding p ate.

Fig. 7 is an axial'section of a stretcher nut havin two threads. v

.Fig. 8 s ows a modified form of stretcher I employing the nut shown inFigure 7. a

Fig. 9 shows a modification in which the stretcheris used with rigid bracing rods.

In the manufacture of the stretcher, there is prepared (Fig. 1) a blank 1, having a central bore 2 having the diameter of the chamber desired, and the end of the blank which is to be pressed to asmaller diameter is provided with the annular ribs 3 in suitable. number,- cooperatin with recesses of corresponding form int c tool 4 used for the ressin operation.

T e bla is properly held in the longitudinal direction by stops such as the one shown at 5, and the tool 4 is operated in the usual manner in order to reduce the diameter of the corresponding part of the blank 1. Dur' this operation, the metal of the blank is hel 85 against lengthwise. motion by its ribs 3 which fit into the matrix, so that the metal will be ressed together, with a certain contraction of its fibres, thus forming a portion 6 of reduced diameter. This part has a, greater strength on account of the compactness of its fibres, so that when tapped, the thread-will show a great strength, and the metal will offer no cracks or flaws. v

In the manufacture of stretchers, it is thus feasible to obtain, as shown in Figure 3, tapped pieces or nuts such as 7 having an internal portion or chamber at 8 of larger diameter than the tapped end 9, each nut having an eye 10, known per so, by which it is atthreads 9 running in opposite directions (one' right hand and the other left hand) are illustrated in Fig. 4 in conjunction with a screw 13 interposed between such nuts and having right and left hand threads to fit those of the nuts, thus forming a turnbuckle or stretcher which can be adjusted by turning the screw 13 in any usual or approved manner.

The element which holds the stretcher against all change of adjustment, consists of a removable plate 14 which is secured to the screw 13 by a pin 15 and carries at its ends the straps 16 whose straight branches 17 cooperate, with proper ad ustment, with the flat parts 18 of the nuts 11-12.

To regulate the tension of cables, rods or the like which are to'be stretched by the said device, the said plate 14'16 is removed, after taking out the pin 15. The screw can then be turned to properly stretch the cable and when this operation has been performed, the flat parts 18 are brought into proper'position, and upon these are fitted the straps 16 of the plate 14, the latter being then secured to the screw 13 by the pin 15.

In this device, the ribs 3 formed on the blank during the manufacture of the nut (Fig. 1) serve to prevent the said plate from beingmounted in place on the nuts before these latter are engaged for a determined length on the screw 13. p

' The method of manufacture described with reference to Figures 1 and 2 can also be emrope device, so that the stretcher may be used for guy ropes of all kinds.

According to the invention, stretchers can be manufactured by the forging process which afterthe pressing operation will have a great strength whereby the proper holding of the thread will be assured, Stretchers of light weight can be thus produced which are stronger than the ones usually employed, and these will also beinexpensive. On the other hand, the use of the holding plate which is put in place only'afte'r th'e cable has been properly stretched, will afford themore' ready application of the-stretcher and furthermore, the use of a tapped part of determined length in the nut will provide means for measuring with all desired precision the effort to be exercised for the stretching of the cable.

The said stretchers may consist of any suitable metals and may be pressed hot or cold according to the case.

The aforesaid pressing process is applicable to the manufacture of all articles for whatever purpose, whether plain or tapped.

What I claim is. 1. The method of manufacturing a tubular metal article having a reduced portion adapted to be threaded internally, which consists in taking a tubular blank whose bore c'orre sponds to that of the body of the article to be produced, and exerting a transverse inward pressure on that portion of the blank which is-to form said reduced portion of the article, while holding the metal at the outer peripheral surface of said portion of the blank against longitudinal flow, whereby the pressure exerted against said portion will operate not only to reduce said portion but to increase the density and strength of the metal in said portion. '1

2. The method of manufacturing a tubular metal article having a reduced portion adapted to be threaded internally, which consists in takin a tubular blank whose bore correspon s to that of the body of the article to be produced, and exerting a transverse inward ressure on that portion of. the blank which 1s to form said reduced portion of the article, while holding the metal at the outer peripher- 7 a1 surface of said portion of the blank against longitudinal flow, by the interlocking of circumferential ribs and grooves formed on the 1 blankand on the adjacent face of the pressure-exerting device, whereby the pressure exerted against said portion will operate not only to reduce said portion but to increase the density and strength of the metal in said 3. T e method of'manufacturmg a tubular metal article having a reduced portion adapted to be threaded internally, which consists in taking a tubular blank whose bore corresponds to that of the body of the article to be produced and whose outer surface has an annular rib projecting therefrom, and exerting a transverse inward pressure on thatportion of the blank which has said annular rib, while holding the metal at the outer periphera1 surface of said portion against longitudinal flow by the interlocking of said annular rib with a mating annular groove formed on the adjacent face of the pressure-exerting device,

whereby the pressureexerted against said portion will operate not only to reduce said portion in diameter but to increase the density and strength of the metal in said portion.

In testimony whereof I have hereunto set mychand at Paris this fifth day of March,

' ALBERT PAUL' STREIT. 

